Rosacea is a skin disease that affects the middle third of the face, causing persistent redness over the areas of the face and nose that normally blush -- mainly the forehead, the chin and the lower half of the nose.

The tiny blood vessels in these areas enlarge (dilate) and become more visible through the skin, appearing like tiny red lines (called telangiectasias).

Pimples can occur in rosacea that resemble teenage acne. In fact, rosacea is frequently mistaken for acne and is also referred to as acne rosacea.